I'll be adding a Taurus electric fan to replace the weak Zirgo fan, so my 70A stock alternator will not likely be up to the task. My battery is mounted in the trunk, so the charge wire will be longer than one with a battery mounted in the engine bay. What is the rule of thumb for wire size for a 130A 3g alternator? Wire length will be roughly 8ft, maybe a tad longer. I currently have either 6ga or 8ga wire meant for a power feed to an stereo amplifier (fine strand wires). I'll double check on that size, but I have a hunch that even the 8ga should be fine. Let me know if you agree.
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130a 3g alternator charge wire size for battery in trunk?
- Thread starter buening
- Start date
It looks like 6ga is the minimum: http://www.allfordmustangs.com/forums/attachments/classic-tech/21965d1166149617-late-model-alternator-early-harness-3ginstall.jpg
I usually use the chassis wiring category from a chart like this:
http://www.powerstream.com/Wire_Size.htm
Personally, I'd be using something rated ~20% more than the intended load, just to be on the safe side.
http://www.powerstream.com/Wire_Size.htm
Personally, I'd be using something rated ~20% more than the intended load, just to be on the safe side.
camachinist
Member
Assuming your starter solenoid (presuming OEM style starter arrangement) is still in the engine bay area, why not just run your power wire to the battery post there and let the battery cable do the work? It's sized (I think I used 0 gauge on the race car, with twin batteries in the trunk) to handle the amps.
68EFIvert
Well-Known Member
I am running 0 gauge from the battery in the trunk to the solenoid in the engine bay. I know a no no. I am running 2 guage from my 3G alternator to the solenoid. Works great for me. Just make sure you put a mega fuse on the wire from the alternator to the solenoid. IIRC mine is 175 amp. I purchased the kit from fordfuelinjection.com initially. When I redid my accessory drive setup I needed a longer cable from the alternator and made my own from welding wire.
Guess I should have specified, the solenoid is in the trunk along with the battery. The wire in the car currently is an 8ga. According to that table from powerstream, it appears a 4ga would be the bare minimum for the charge wire. This looks like it could turn into a bit more work than I really need to add at the moment. I may put it off until after I get the car on the road from the transmission install. If anything I'll work on everything else except for that and see how much time I have left before the baby arrives.
Looking at the diagram again, did anyone just run the "A" yellow wire from the internal regulator to the charge "B+" post on the back of the alternator?? The diagram says at the top to do this, but then they have a yellow wire going to the starter solenoid side post. I don't see why I couldn't, just thought I'd ask.
Also, looking at the 70 wiring diagram the charge wire splices with a few other wires. There is a plain Red wire that goes to the instrument cluster, a Yellow that also goes to the instrument cluster, and a Black/Yellow that goes to the Ignition Switch, Headlight Switch, and goes through the fuse box to the turn signal switch. How did you handle splicing into such a large 4ga charge wire?
Also, looking at the 70 wiring diagram the charge wire splices with a few other wires. There is a plain Red wire that goes to the instrument cluster, a Yellow that also goes to the instrument cluster, and a Black/Yellow that goes to the Ignition Switch, Headlight Switch, and goes through the fuse box to the turn signal switch. How did you handle splicing into such a large 4ga charge wire?
guruatbol
Always on vacation!
I want to do the same thing in the 65 but am unsure what to do with the wires. Do I need to splice a larger wire into them and take all the wires to the trunk via some auto conduit?
How should this be done to do it right...??? I don't want to mickey Mouse it...
Mel
How should this be done to do it right...??? I don't want to mickey Mouse it...
Mel
Here is what I've come up with. I'll be buying this, since my alternator is a new one and didn't come with any connectors: http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=270456601715&viewitem=&sspagename=STRK%3AMEWAX%3AIT
My harness is already cut from relocating the battery and solenoid to the trunk, but basically I'll use the above connector and connect the remaining green wire to the green/red wire near the alternator harness. I'll cut the black stock charge wire and connect it to the B+ charge post. This wire provides power to the things I had described in a previous post above. I'll then run a separate 4ga charge wire to the trunk, routing it through the firewall on the passenger side and then through the sill plate and then over the wheelwell. I already have a 0ga starter wire, so I may not have enough room to go this route. I'll cross that road when I get there.
My harness is already cut from relocating the battery and solenoid to the trunk, but basically I'll use the above connector and connect the remaining green wire to the green/red wire near the alternator harness. I'll cut the black stock charge wire and connect it to the B+ charge post. This wire provides power to the things I had described in a previous post above. I'll then run a separate 4ga charge wire to the trunk, routing it through the firewall on the passenger side and then through the sill plate and then over the wheelwell. I already have a 0ga starter wire, so I may not have enough room to go this route. I'll cross that road when I get there.